In current imaging systems that employ spatial light modulators comprising individually addressable pixels, light incident to the pixels of the spatial light modulator is modulated by the pixels of the spatial light modulator. By setting the pixels at an ON state, the incident light is directed onto a screen so as to generate bright image pixels on the screen. Such modulated light is referred to as ON-state light; and the spatial-light-modulator pixels at the ON state are referred to as ON-state pixels. By setting the spatial-light-modulator pixels at an OFF state, the incident light is directed away from the screen so as to cause dark image pixels on the screen. Such modulated light is referred to as OFF-state light; and the pixels at the OFF state are referred to as OFF-state pixels. For obtaining a high contrast ratio of the displayed images on the screen, the OFF-state light is dumped or discarded by the imaging systems, which on the other hand, reduces the optical efficiency of the imaging system.
Therefore, it is desired to have a mechanism to recycle the OFF-state light such that the recycled OFF-state light can be directed to the screen so as to improve the optical efficiency of the imaging system.